Method and system of catalyst hydrodrilling with wastewater treatment and recycle

Abstract

The present invention is directed to an improved multi-step hydro drilling process that combines hydro drilling, hydro cutting technology to remove the fused catalyst in the reactor where water is treated and recycled in a proprietary closed-loop system. Use of an adjustable hydro drill head facilitates faster and more convenient switching of spray pattern suitable for operations.

Description

METHOD AND SYSTEM OF CATALYST HYDRODRILLING WITH WASTEWATER TREATMENTAND RECYCLEField of the Invention

[0001] The present invention relates generally to a method and system for catalyst handling for refinery or petrochemical industry and particularly to methods employing hydro drilling together with treatment and recycling of wash water.

[0002] Solid catalysts are widely used in industrial catalytic reactors, particularly in petroleum refining. Processes like catalytic distillation, fluid catalytic cracking, hydrocracking, reforming, and hydrotreating are extensively documented. The catalysts used in these processes come in various chemical compositions and forms, such as powders, particles in fixed, moving, fluidized, or slurry beds, and porous structures like monoliths, foams, and gauzes. Depending on the specific process, reactors may contain multiple catalyst beds or be configured with multiple reactors operating in parallel orseries to manage the flow of reactants and products.

[0003] Over time, catalysts lose their effectiveness in facilitating the desired chemical reactions. This deactivation often results from gradual contamination (e.g., sulfur or metal poisoning) or the buildup of by-products from side reactions, such as coke deposits. When the reactor’s performance declines significantly, the spent catalyst must be replaced with fresh material to restore productivity.

[0004] For the reasons above related to the processes for manufacturing fuels and chemicals and the yields of chemical reactions, it is necessary to periodically transport, drain and replace spent catalyst contained in reserves and / or reactors.

[0005] Process reactors with internal dump nozzles enable the flow of spent catalyst from each bed to the bottom external dump nozzle(s). However, this system is not suitable for handling coked, agglomerated, or oversized catalyst, including large-scale fused masses where the entire bed becomes a single, non-granular mass. In such cases, alternative removal methods are required, typically involving time-consuming manual procedures. These procedures may include the use of tools such as jackhammers and air lances, as well as the implementation of controlled fracturing and hydro-lancing techniques.

[0006] U.S. Pat. No. 4,630, 779A describes a method of removing consolidated waste catalyst from a reactor by forming at least one hole in it, then filling the holewith hydrative expansive fracturing agent in the presence of water, waiting until fracturing occurs and then discharging the fractured catalyst from the reactor.

[0007] The removal of spent catalyst presents significant safety and economic challenges. In the context of multi-stage residue hydrodesulfurization units, the process of catalyst removal and subsequent replacement can extend up to 20 days, resulting in substantial operational costs. Therefore, there exists a critical need for the development of a system and method capable of achieving both rapid and efficient removal of spent catalyst.Summary of the Invention

[0008] The present solution effectively combines hydro drilling and hydro lancing technologies to facilitate the removal of virtually all catalyst material within the reactor without necessitating personnel entry into the vessel. This approach demonstrates a substantial reduction in water consumption compared to alternative techniques, as all water utilized within the system undergoes treatment and is subsequently recycled within a closed-loop configuration. Furthermore, the elimination of mechanical hammering safeguards the integrity of the reactor's internal components.

[0009] The process initiates by establishing a clear path through the spent catalyst bed which involves a hydro drilling process that proceeds downward from the top of the vessel to create a central core. This core facilitates the efficient removal of water and drill cuttings from the vessel.

[0010] Concurrently, hydro lancing operations are conducted in an upward direction from the bottom through the vessel dump nozzles. This simultaneous action provides a clear exit path for the effective removal of water and cutting materials from the vessel.

[0011] After establishing a clear flow path, the drill is retracted, and the adjustable hydro drill head / bit is reconfigured. The adjustable hydro drill head / bit can be adapted to produce a variety of spray patterns depending on the stage of work, catalyst material type, and hardness. The drill head / bit undergoes a sequence of reconfigurations to remove the spent catalyst, with cuttings flushed out through the bottom dump nozzles.

[0012] In certain multi-bed reactor configurations, the drilling process can be conducted directly through the inter-bed support structures via centrally located openings. This unique approach enables the simultaneous discharge ofspent catalyst from both beds through the bottom dump nozzles, effectively streamlining the removal process.

[0013] The water recirculation system significantly reduces water consumption during catalyst removal operations. Compared to traditional methods, which typically require over 10 million liters of water, the system ensures that less than 15% of this volume necessitates wastewater treatment.

[0014] Catalyst replacement schedules exhibits significant reduction due to the combination of faster reactor cool-down times and higher, more consistent unloading rates. This enhancement results in a guaranteed reduction in the overall change-out duration. Consequently, this approach delivers a substantially more effective, efficient, and sustainable solution, ultimately leading to increased value and a reduction in overall operational costs.

[0015] This invention describes a process for removing spent, hardened, fused, or agglomerated catalyst from a process vessel containing one or more catalyst beds optionally supported by structural packing. Catalyst vessels may be equipped with one or more dump nozzles situated at the base orwithin the vessel wall.The process comprises: a) hydro drilling a central core through the one or more catalyst beds along an axis extending vertically downward the length of the process vessel b) hydro lancingupwards from the one or more dump nozzles, to meet with the central core c) hydro cutting the spent, hardened, fused, or agglomerated catalyst into catalyst masses, and passing the drill cuttings comprising spent catalyst masses and water out through the one or more dump nozzles d) separatingthe catalyst material from the water e) filteringand treatingthe water f) storing the filtered and treated water g) reusingthe stored filtered and treated waterfor hydro driling, hydro lancing and hydro cutting steps of a), b) and c)

[0016] Preferably, the removal operation of spent hardened, fused, or agglomerated catalyst commences with the installation of a portable drilling rig. This rig is positioned on the top flange of the process vessel, centrally aligned with the central manhole or off-take nozzle.

[0017] Preferably, the removal operation of spent hardened, fused, or agglomerated catalyst beds commences with the drilling of a central pilot hole. This hole is drilled through the approximate center of the catalyst bed, commencing at the top and progressing downwardly.

[0018] The central positioningof the drilling operation facilitates unobstructed passage through bed support packing in the event of a multi-bed vessel configuration.

[0019] Advantageously, the drilling rig incorporates a standard high-pressure drill string. This component serves to enhance stability, facilitate vertical movement, and provide precise control of the adjustable hydro drill head / bit. This configuration ensures the accurate and controlled movement of the high- pressure hydro drill head / bit as it traverses through the hardened catalyst materials.

[0020] The adjustable hydro drill head / bit is adapted to produce a variety of spray pattern. The adjustable hydro drill head / bit is provided with a plurality of ports, which can be either plugged, or opened and installed with interchangeable and individually configurable high-pressure waterjet nozzles. This design flexibility allows for efficient adaptation to various drilling stages, the specific characteristics of the catalyst material, and the material's hardness. A faster turnaround is also achieved compared to having to withdraw and replace the entire hydro drill head / bit with a separate hydro drill head / bit that produces a different fixed spray pattern.

[0021] The utilization of high-pressure water by the adjustable hydro drill head / bit for the removal of hardened / fused catalyst bed material eliminates the potential for mechanical damage to the vessel's internal components, unlike techniques involvingjackhammeringor localized fracturing.

[0022] In a preferred embodiment, the process commences with hydro drilling of a central, vertically oriented core. This core possesses a minimum diameter of 100 mm, with a preferred range extending from approximately 100 to 160 mm. Drilling operations proceed downwardlyfrom the apex of the catalyst bed.

[0023] Concurrently with the hydro drilling of the central core, a hydro lance is strategically positioned at the dump nozzle. The hydro lance is utilized to create an opening within the bed, ensuring its alignment with the drilled core. This action establishes a clear drainage path, facilitating the flow of drill cutting slurry from the core to the dump nozzle opening. In the case of process vesselsequipped with multiple dump nozzles, this lancing and drainage procedure is repeated for each nozzle.

[0024] Preferably, hydro lancing operations are conducted continuously through the dump nozzle throughout the duration of the drilling process. This continuous action serves to maintain the integrity of the opening and prevent the accumulation of drill cuttings, thereby ensuring unobstructed flow of the slurry to the dump tank.

[0025] The preferred lancing pressure used to maintain the opening between the dump line and the central core is between 1 ,350 Bar (20,000 psi) and 820 Bar (10,000 psi), more preferably 1 ,000 Bar (15,000 psi).

[0026] The adjustable hydro drill head / bits are designed to accommodate a range of sizes and feature individually removable, configurable high-pressure waterjet nozzles. Each nozzle delivers a high-pressure waterjet, allowingforvarious functions including drilling, cutting, and washing catalyst material out of the vessel. Preferred drill head diameters are between 100mm to 150mm, with a more preferred size of 125mm.

[0027] The preferred operating pressure during drilling ranges from 1,350 Bar (20,000 psi) to 820 Bar (10,000 psi), with 1 ,000 Bar (15,000 psi) being more suitable. These pressures serve as a reference point, and more precise nozzle pressures can be calculated based on factors such as pipe length and elevation differences.

[0028] In a preferred embodiment, the initial configuration of the adjustable hydro drill head / bit, utilized for the creation of the pilot hole or core, incorporates two waterjet outlets oriented downwardly when the hydro drill head / bit is in its normal operating position.

[0029] After drilling the pilot hole or core to the vessel bottom, the hydro drill head / bit is withdrawn and reconfigured to produce a different spray pattern suitable for widening the central core.

[0030] The adjustable hydro drill head / bit typically equipped with six ports, is designed to deliver water jets at a pressure of 1,000 Bar (15,000 psi) in both horizontal and angled directions. This reconfigured hydro drill head / bit facilitates the widening of the central core. The spray pattern encompasses:• two ports directed downwardtwo ports angled downward at approximately 45 degrees two ports directed horizontally

[0031] Advantageously, the adjustable hydro drill head / bit exhibit interchangeability and is equipped with individually configurable high-pressure waterjet nozzles. This design feature allows for adaptability to the specific requirements of each drilling operation or the unique characteristics of the material being drilled. The number, direction, and type of nozzles can be dynamically adjusted and modified as required.

[0032] It is preferable to conduct drilling operations utilizing the adjustable hydro drill head / bit in the second configuration in a top-down approach. The primary objective of this stage is to widen the central core from an initial diameter of 100 mm to an approximate diameter of 1200 mm. This enlargement process is specifically designed to exclude areas occupied by support packing, if present.

[0033] Subsequent to the widening of the central core, the adjustable hydro drill head / bit undergoes adjustment to enable radial delivery of concentrated jets of water. These jets, operating at a high pressure of preferably 1 ,000 Bar (15,000 psi), are specifically elected to efficiently remove the majority of catalyst material that has adhered to the vessel walls.

[0034] In the third configuration, the adjustable hydro drill head / bit undergoes reconfiguration, having four active ports. These ports are designed to deliver waterjets in a horizontal direction, facilitatingfurther enlargement of the central core hole as the drill head executes rotational movements. The spray pattern encompasses:• two ports directed downward.• two ports directed horizontally

[0035] The adjustable hydro drill bit's third configuration facilitates access to more distant areas on the vessel shell walls, particularly those further from the spent catalyst bed's centre. High-pressure waterjets effectively dislodge and remove the caked catalyst.

[0036] The catalyst cuttings and water slurry are discharged from the process vessel through dump nozzles. This slurry then flows into a vessel catch trough before entering a spiral classifier for separation of bulk solids and liquids. The separated slurry is stored and subsequently processed to recover water for reuse.

[0037] This method significantly enhances worker safety by eliminating the need for personnel to enter the vessel during the removal of nearly all fused catalyst. The unloading process can be carried out safely under normal atmospheric conditions due to the passivating effect of water. Importantly, this method ensures the removal of the spent catalyst without causing any damage to the internal components or the outer shell of the vessel.

[0038] The underflow from the spiral classifier is a slurry containing water and catalyst fines. Filtration systems may include, but are not limited to:• a Lamella Clarifier• Cyclone Separators• Bag Filters• Candle Filters• Resin Filter• Centrifuge• Tri canter• Vacuum Distillation• ARJ Filtration• Settling TanksThese systems work sequentially to capture fines larger than 1 pm, aiming for a 99.99% removal rate of 1 pm fines and a Total Suspended Solids (TSS) concentration below 103 mg / L.

[0039] The underflow treatment process incorporates an oil removal stage. The objective is to reduce the oil content in the water to a level below 250 mg / L. Subsequently, additives are introduced to neutralize the water, ensuring that the pH level falls within the desired range of 6.0 to 8.0, with a preferred value of 7.0.

[0040] Treated and filtered water is stored in a holding tank for reuse in hydro drilling and hydro lancing operations throughout the catalyst removal process. The recycling of used water ensures a reliable and uninterrupted water supply for drilling operations. Recirculated water undergoes continuous treatment, and water analysis of the clean water tank is conducted regularly to confirm its suitability for eventual safe discharge.

[0041] A significant advantage of this system lies in its ability to create a complete closed-loop water recycling system encompassing hydro drilling, hydro lancing, and treatment operations.

[0042] The present solution exhibits broad applicability, effectively addressing a wide range of reactor types with diverse catalyst bed configurations. Furthermore, it demonstrates the capability to effectively remove various forms of deactivated catalysts, including hardened, coked, fused, and sulfurized materials.Brief Description of the Drawings

[0043] Fig 1 is a simplified schematic illustration of a preferred embodiment of the present invention.

[0044] FIG. 2 is a flow diagram illustrating a method for the removal of fused, coked, and agglomerated spent catalyst from a process vessel, according to one exemplary embodiment of the present disclosure.

[0045] FIG. 3 is a flow diagram illustrating a method for the removal of fused, coked, and agglomerated spent catalyst from a process vessel, according to a second exemplary embodiment of the present disclosure.Detailed Description

[0046] Referring to Fig. 1 , water is withdrawn from clean water storage tank 32 via line 33 and pumped by high pressure water jet pump 34 to a pressure of approximately 1,000 bar (15,000 psi).

[0047] Pressurized water from pump 34 is distributed through manifold 35 to flexible hoses 36, 37, and 38, supplying hydro drill 1 and hydro lances 9 and 10. Hydro lances 9 and 10 enter process vessel 6 through catalyst dump openings 7 and 8. These hydro lances 9 and 10 maintain the dump openings clear to facilitate the flow of catalyst cuttings during drilling operations.

[0048] "Hydro" in this context refers to the use of water in liquid form. The terms "hydro drilling," "hydro cutting," "drilling," and "cutting" are used interchangeably. "Cutting" often refers to radial operations from the central opening during initial catalyst removal.

[0049] Drilling pressures are controlled by regulating the pump outlet pressure, a critical factor in the successful implementation of this catalyst removal process. Pump 34 incorporates an internal rupture disc as a safety pressure relief. An external Pressure Relief Device (PRD) provides an additional layer of safety.

[0050] Water from line 36 is introduced to process vessel 6 through drill string s during drilling operations. A hydraulic drill rig moves hydro drill 1 up and down within the process vessel 6. The portable hydraulic drill 1 is powered by its own power supply 3 and can be relocated after catalyst removal and used on other reactor vessels within the facility.

[0051] Water enters hydraulic drill 1 through a special high-pressure swivel 4, passing within drill string pipe 5 and exiting through adjustable hydro drill head / bit 39. The high-pressure swivel 4 when adapted to a standard drill string supports drill string rotation while maintaining high-pressure water flow.

[0052] Drill pipe sections are added or removed by disconnecting the pipe at the swivel 4, securing it with a clamping device, and adjusting the swivel's position as needed. The hydraulic control system, operated at an operator control panel 2, controls drill rig movement, drill pipe rotation, and water flow to the drill rig. Drill strings and bits are designed to navigate the relatively small openings in the support packing between reactor beds.

[0053] Typically, catalyst is supported on wire mesh screens, which are in turn supported by extensive packing structures due to the significant weight of the catalyst bed. This structure often includes I-beams or girders rigidly attached to the reactor vessel's innerwalls.

[0054] Other internals, such as nozzles or rings and gas / liq uid distribution trays, may also be present. These internals can complicate the process, as drilling preferably creates a central opening along the reactor's vertical length to facilitate radial catalyst removal. To accommodate this, these internals are preferably designed with a central opening, ideally at least 200 mm in diameter (orwidth if rectangular in shape).

[0055] The drilling process typically involves at least two steps, preferably three. The adjustable hydro drill head / bit 39 is reconfigured to produce a spray pattern suitable for each step as illustrated in Fig 3.

[0056] For the first step, a cutting pattern (one or more downwardly pointed water outlets) is used to drill a central hole from the top of the top fixed bed to the bottom bed.

[0057] The drill string is then retracted, and the adjustable hydro drill head / bit 39 is reconfigured to deliver at least two concentrated water streams radially outward from the central opening, cutting into the catalyst bed. Thereconfigured hydro drill head / bit 39 may include two horizontal outlets, two outlets angled 45 degrees upward, two angled 45 degrees downward, and two directed vertically downward to assist in clearing drill cuttings.

[0058] Cutting can occur from top to bottom or bottom to top, buttop-down operation is preferred.

[0059] In the preferred three-step operation, the adjustable hydro drill head / bit 39 is reconfigured with four ports in the third step. These ports deliver water jets in a horizontal direction, further enlargingthe central core hole as the drill head rotates. The spray pattern includes two downward-directed ports and two horizontal ports.

[0060] The preferred steps can be used in overlapping or cyclic fashion. For example, the first or second hydro drill head / bit configuration may be used again even afterthe process has progressed to using the second orthird configuration for part of the catalyst removal operation.

[0061] Referring again to hydro lances 9 and 10 at the process vessel 6 bottom, high- pressure water from the main high pressure waterjet pump 34 is routed to these lances to maintain the catalyst dump openings 7 and 8 clear. Lances are inserted through the dump nozzles to clean the nozzle areas and establish a connection to the central hole created by the drilling operation.

[0062] A slurryof water and wet catalystflows out of the reactordump nozzles ? and / or 8 into process vessel catch trough 11 . From the catch trough, the slurry is passed via line 15 to the spiral classifier 13.

[0063] The larger pieces of catalyst are separated from the slurry by the spiral classifier 13 and transferred to solid discharge bins, big bags, or trackable containers 14 for removal. Other separating means including rotating drum trommel can be used for this step.

[0064] Slurry water from the spiral classifier underflow accumulated in underflow basin 12 is transferred via pump 17 and lines 16 and 18 to the dirty water tank 19. The slurry is then fed at a rate of 10-100 m3 / h to a lamella clarifier 23 via pump 21 and lines 20 and 22. The lamella clarifier 23 uses a set of plates to separate solid particles from the liquid slurry. Clarified liquid flows from lamella clarifier 23 through line 24 into the filter feed tank 25.

[0065] The slurry is now nearly clear water. The final filtration step via filters 29 removes particles larger than 1 pm, ensuring that Total Suspended Solids (TSS) are less than 103 mg / L and free oil content is less than 250 mg / L. The water is also neutralized to a suitable pH range using additives.

[0066] The filtrate flows to the clean water storage tank 32, which serves as the feed supply for the high pressure waterjet pump 34.

[0067] Effluent from the filters is collected in drums and IBC containers 31 .

[0068] If necessary, water can be drawn off from the stream after a first filtration step of standard bagfilterto a mud pump 41. Mud pump 41 is a high-pressure water pump designed to handle lowerwater quality and can deliver water to hydro drill 1 and hydro lances 9 and 10.

[0069] After spent catalyst removal and completion of any final work on the process vessel internals, process vessel 6 is closed at the bottom, and the operation of recharging the reactor vessel with fresh catalyst is commenced.

[0070] The present invention significantly reduces water consumption during catalyst removal operations. Compared to traditional methods, which typically require over 10 million liters of water, the system ensures that less than 15% of this volume necessitates wastewater treatment.

[0071] To mitigate potential environmental concerns, the recirculated water is analyzed for the presence of exotic metals, such as vanadium. If these metals are detected in concentrations exceeding regulatory limits, the treated water may require further processing at a wastewater treatment plant. However, if the water meets all regulatory standards, it can be safely discharged directly without additional treatment.

[0072] List of elements in figures

Claims

CLAIMS:1 . A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel containing one or more catalyst beds optionally supported by structural packing and containing one or more dump nozzles comprising: hydro drilling a central core through the one or more catalyst beds along an axis extending vertically downward the length of the process vessel; hydro lancing upwards from the one or more dump nozzles, to meet with the central core; hydro cutting the spent, hardened, fused, or agglomerated catalyst into catalyst masses, and passing the drill cuttings comprising catalyst masses and water out through the one or more dump nozzles; separating the catalyst masses from the water; filtering and treating the water; storing the filtered and treated water; and reusingthe stored filtered and treated waterfor hydro drilling, hydro lancing and hydro cutting.

2. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 1 wherein hydro drilling of the central core is commenced from the top of the uppermost catalyst bed in the process vessel.

3. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 1 wherein the one or more dump nozzles are maintained open by continuous hydro lancing through the dump nozzles.

4. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 3 wherein hydro lancing is conducted at a shallow angle from the horizontal through the dump nozzles.

5. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 1 wherein a same adjustable hydro drill head is used for the hydro drilling and hydro cutting steps.

6. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 5 wherein the same adjustable hydro drill head is adapted for producing a plurality of spray pattern.

7. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 6 wherein the same adjustable hydro drill head is configured to produce two waterjets oriented downwardly for the hydro drilling step.

8. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 7 wherein the same hydro drill head is withdrawn after the hydro drilling step and manually configured to produce a different spray pattern for the hydro cutting step.

9. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 8 wherein the same adjustable hydro drill head is configured to produce two waterjets directed downwardly, two waterjets angled downward at a proximately 45 degrees and two waterjets directed horizontally for the hydro cutting step.

10. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 9 wherein the same adjustable hydro drill head is withdrawn after the hydro cutting step and manually configured to produce a different spray pattern for a next hydro cutting step.11 . A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 10 wherein the different spray pattern comprises two waterjets directed downwardly and two water jets directed horizontally.

12. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 1 wherein the operating water pressure ranges from 1 ,350 Bar (20,000 psi) to 820 Bar (10,000 psi), with 1,000 Bar (15,000 psi) being more suitable.

13. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 1 wherein separation of the catalyst masses from the water is performed with a spiral classifier or a rotating drum trommel.

14. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 1 wherein filtering the water comprises a series of filtration steps.

15. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 14 wherein water is drawn off after a first filtration step for reuse for hydro drilling, hydro lancing and hydro cutting.

16. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 1 wherein a portable hydro drilling rig is used to perform the hydro drilling and hydro cutting steps.

17. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 16 wherein the portable hydro drilling rig is devised by adapting a standard hydraulic rock drill with a high-pressure swivel.

18. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 1 wherein the central core has a diameter no less than 100 mm, with a preferred range extendingfrom approximately 100 to 160 mm.

19. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 1 wherein the central core has a diameter no less than 100 mm, with a preferred range extendingfrom approximately 100 to 160 mm.

20. A method for removing spent, hardened, fused, or agglomerated catalyst from a process vessel according to claim 1 wherein the central core is widened to an approximate diameter of 1200 mm during the hydro cutting step.

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